The present invention relates to generally to vacuum cleaner brushrolls, and, more specifically, to vacuum cleaner brushrolls having new and improved bristle tuft pattern that enhances the performance of the brushroll.
The typical vacuum cleaner brushroll includes a spindle that carries rows of bristle tufts which sweep across the carpet during rotation of the brushroll. Conventional brushrolls have the bristle tufts arranged to provide a sweeping contact with the carpet along the length of the brushroll in every rotative position. The rows may be parallel to the longitudinal axis of the spindle as disclosed in U.S. Pat. No. 3,828,387 to Liebsher or they maybe helically oriented as disclosed in U.S. Pat. No. 4,387,479 to Mertes and U.S. Pat. No. 6,530,106 to Brundula.
As shown in both the Mertes and the Brundula patents, the rows of bristle tufts may extend in the same helical direction from one end of the spindle to the other or they may form reverse helixes. In certain embodiments of the Brundula patent, the helical rows are made up of tufted segments that are parallel to the axis of the spindle. In other embodiments, the tufted segments are helically oriented. In either case, the helical twist is large, for example, 760xc2x0, in order to ensure bristle contact with the carpet along the length of the spindle.
The present invention provides a new and improved vacuum cleaner brushroll characterized by a bristle tuft pattern that promotes an up and down movement of the carpet during rotation of the brushroll. The unique up and down motion of the carpet that occurs during rotation significantly enhances the cleaning performance of the brushroll.
As used herein the term xe2x80x9crowxe2x80x9d means a grouping of aligned bristle tufts on a helix.
The term xe2x80x9csectionxe2x80x9d means a portion of the brushroll defined by rows of bristle tufts that are rotationally or angularly spaced from the rows of adjacent brushroll sections.
The term xe2x80x9cdwell positionxe2x80x9d means a position of brushroll rotation in which the rows of bristle tufts along at least one-half the length of the brushroll are not in sweeping contact with the carpet. In a dwell position, the portion of the carpet out of sweeping contact by the bristles will be drawn up toward the mouth of the sweeper nozzle to produce an up and down wave motion of the carpet during brushroll rotation that improves the cleanability performance of the brushroll.
The term xe2x80x9chelix rotationxe2x80x9d means the helical twist of a row of bristle tufts about the longitudinal axis of the brushroll.
In accordance with the invention, the new brushroll comprises a spindle having first and second ends and a longitudinal axis of rotation, and rows of bristle tufts arranged in sections along the length of the spindle with the rows of each section being rotationally or angularly spaced from the rows of adjacent sections. The orientation of the rows of each section and the rotational spacing between rows of adjacent sections form multiple dwell positions during each 360xc2x0 of brushroll rotation.
The brushroll can have from three to eight sections. The number of rows of tufts in each section can vary, but the most effective dwell positions occur with two rows in each section. The rotative or angular spacing between two rows in a section can range from 160xc2x0 to 200xc2x0, with the most preferred spacing being 180xc2x0 so that the two rows are diametrically opposed.
The rotational or angular spacing between the rows of tufts of adjacent sections can also vary. According to one embodiment of the invention, the rows of tufts are helically oriented and extend in the same helix direction. In this embodiment, the helix rotation of the rows and the rotational spacing between the last tufts of one section and the first tufts of the adjacent section form a dwell position extending the length of the brushroll every 90xc2x0 of rotation. In another embodiment, the rows of tufts along one-half of the brushroll extend in one helix direction, while the rows of tufts along the other one-half of the brushroll extend in a reverse helix direction. The helix rotation of the rows and the rotational spacing between the last end tufts of one section and the first end tufts of the adjacent section form a dwell position along one-half the brushroll length every 90xc2x0 of rotation.
A fuller understanding of the invention will be had from the following detailed description of its embodiments and the accompanying drawings.